1. Field of the Invention
The present invention relates to a tire pressure gauge and, more particularly, to a tire pressure gauge having lighting means for use in a dark place.
2. Description of Related Art
A conventional tire pressure gauge has an air nozzle adapted for fastening to the air valve of a vehicle tire. When fastened to the air valve of a vehicle tire, the stopper pin of the air nozzle is opened enabling pressurized air to pass from the vehicle tire into the casing of the tire pressure gauge to move a piston in the casing against a compression spring, thereby causing the piston to move a scale out of the casing to at as an indicator of the air pressure of the vehicle tire. The graduations of the scale cannot be clearly seen when a user measures the vehicle tire pressure in a dark place or the place where no sufficient illumination is provided.
Therefore, it is desirable to provide a tire pressure gauge that is accompanied with a lighting means.
It is the main object of the present invention to provide a tire pressure gauge, which has lighting means for illumination so that the user can use the tire pressure gauge to measure the tire pressure of the vehicle tires in a dark place. It is another object of the present invention to provide a tire pressure gauge having lighting means, which enables the user to detach the lighting means from the tire pressure gauge for use as hand-held lighting.
To achieve these and other objects of the present invention, the tire pressure gauge comprises a cylindrical casing, a light penetrable scale mounted in the casing, spring means mounted and supporting the scale in the casing, a piston moved in the casing, a battery and lamp assembly, and an air nozzle fixedly fastened to one end of the casing and adapted for fastening to the air valve of a vehicle tire to guide air pressure from the vehicle tire into the casing to move the piston, causing the piston to move the scale out of the casing to act as an indicator of the pressure of the vehicle tire. The battery and lamp assembly may be detachably fastened to one end of the scale outside the casing, or be provided inside the casing. Preferably, the battery and lamp assembly uses a light emitting diode as light source means.